I am writing this letter to outline the benefits of traditional Mud Set installations verses prefabricated substrates such as Wonderboard or other types of cementitious backer boards.
In 1975, the first sheet of Wonderboard was born by inventors Paul E. Dinkel and Theodore E. Clear of Hamilton, Ohio. It took years to make it into the industry. "GlassCrete", USG who had other similar knockoffs came later on around the early 1980's. This product was used in commercial application at first, then slowly made it’s way into residential construction. This product as well as many other products which facilitated the streamlining of construction was born out of necessity for a couple of reasons. First, as our population grew, the demand for more buildings had increased. As the demand grew, time became a major factor in construction. Another reason was many of the older generation of mud setters from the 1940’s and 1950’s had retired by the 1970’s or had died off. The advent of Wonderboard or other prefabricated substrates did not make mud set installations obsolete, it was simply a matter of lack of training for the then up and coming younger tile setters as well as and big corporations bottom line as this would allow them to recruit more installers with less time in training people. I also believe some kick backs were involved from these manufacturers to local building departments as well as some large developers, but that’s another story.
This mindset of "streamlining" rather than properly training people resulted in inferior quality which subsequently brought a windfall of quasi tile setters in the name of progress. Also, as home improvement big box stores came on the scene around the mid 1980's, it allowed home owners to set tile themselves. Again, there is no comparison to REAL tile setting. REAL tile setting requires one to paper, wire their walls, float your mortar 1/2" to 3/4" thick on the walls, plumb and straight, soaking your tile in water, mixing pure portland cement mixed with a little fire clay (to make it more sticky) and setting your tile on the wall you just floated, THAT my friends, is TRUE tile setting and it is how I still set my tile. Cement board, thinset and adhesives is NOT tile setting, sorry. If I could use an example, let's take the Quarter Pounder with Cheese. While this burger may taste good, cheap and cranked out very quickly, it's nutritional value and taste could hardly compare to a burger say that was prepared by a chef or an establishment that actually grills the burger rather than microwave it and does not use substandard materials to make that fabulous burger.
Here is the problem with prefabricated substrates that I see which cannot hold the same qualifications that the traditional mud set can. If your wall is out of plumb, or floor is out of level or has a hump in it, the Wonderboard or any other prefabricated substrate will follow that hump or irregular contour. With mud set, this is not a problem. Tile is like a tape measure on the wall. If there is a flaw in the wall, this will only be magnified by the tile being there, this is why it is so important to make sure the substrate is exactly that, straight.
With Wonderboard or other prefabricated substrates you have seams, with mud set you do not. Prefabricated substrates are nailed to floor and wall studs directly with no water proof membrane, this allows wall and floor deflection which can lead to tile cracking. Mudset is anchored everywhere and is evenly distributed for maximum bond to the floor or wall and every void is filled, the same cannot be said for prefabricated substrates. Years ago, the builder would drop the floor joists 2-3" to accommodate a mud bed for tile.. ahhh those were the days! Try and get a builder to do that today! However, a good 3/4" bed of deck mud that is 4 to 1 ratio and hard packed is just fine. Mud set is more water proof. It has stood the test of time. This method has been used for centuries. I’ve torn out showers and other tile jobs that were mud set and the only reason these showers were decommissioned was because the customer desired a different color, not because they had failed.
The bottom line is this, when it comes to traditional mud set, if this generation knew more about it as their predecessors did, where, in their time, this was common practice, more people would demand this level of skill. Thank you for your time.